Seasonal and Spatial Assessment of Residential Photovoltaic Feasibility in Spain Under Current and Future Climate Conditions Using the APV,N Indicator

This study evaluates the spatial and seasonal feasibility of residential PV integration across 52 Spanish municipalities representing the country’s main urban areas. The assessment is based on the normalized photovoltaic sizing indicator (APV,N), defined as the PV area required to offset electricity demand per square metre of conditioned floor area. Simulations were performed under current climate conditions and future projections for 2050 and 2100 using the RCP4.5 scenario. Results reveal strong climatic and seasonal contrasts. Under current conditions, annual PV generation offsets approximately 17–18% of residential electricity demand. Southern and Mediterranean municipalities show the highest feasibility, with annual APV,N values of approximately 2–2.5, whereas northern and inland regions present severe winter limitations, with APV,N values frequently exceeding 15–20. Summer is the most favourable season, with PV systems covering more than 50% of seasonal demand in several southern municipalities. Future climate projections indicate a progressive improvement in PV feasibility. Under RCP4.5, annual APV,N decreases by approximately 5–10% by 2100, while the production-to-consumption (P/C) ratio improves by about 15–20% relative to present conditions, mainly due to reduced heating demand. The results demonstrate that future climate conditions may improve the viability of residential PV systems in Spain, particularly in southern and coastal urban areas, while northern regions will remain constrained during winter. The study provides quantitative benchmarks for climate-sensitive PV planning and long-term urban energy strategies.